P2X receptors in mammals have been found on peripheral nociceptive sensory neurons and are implicated in sensation. In the fish, a subset of P2X receptors has been found to be localized to a primary sensory neuron called the Rohon-Beard neuron. This cell type is the primary mediator of the touch-evoked escape response in the embryonic zebrafish. By utilizing this dynamic animal model to study a similar phenomenon to sensation in mammals, more direct evidence implicating P2X receptors in sensory pathways can be achieved. To elucidate if P2X receptors mediate the mechanosensory mechanism that underlies this behavior in the fish, studies directly addressing P2X receptor function will be conducted. Through the use of transgenic fish, morpholino technology and calcium indicators, we will demonstrate that P2X receptors are an absolutely necessary component to the mechanosensory mechanism that underlies the escape behavior in the fish. By directly implicating P2X receptors in sensation in this animal model, a better understanding of sensation in the mammal can be gleaned. Ultimately, in human conditions like Causalgia and Rheumatoid Arthritis, direct evidence pointing to P2X receptors will aid in drug discovery.